Because of their ability to synthesize multiple enzymes as well as their environmental acceptability, Bacillus species are employed in a multitude of commercial applications. These applications include cleaning products; drain cleaners; biological digesters; wastewater treatments; use in waste lagoons, grease traps, and plumbing systems; agricultural systems; and aquacultural systems; as well as activity in probiotic administrations. Due to the breadth of materials and environmental conditions which may be encountered in such uses, it is desirable to possess bacterial strains that produce multiple enzymes and which are capable of growth across a wide spectrum of environmental conditions.
Among the Bacillus species which are known to have commercial utility is Bacillus simplex. This species is known to produce proteases (which degrade proteins); lipases (which degrade lipids); esterases (which degrade esters) and amylases (which degrade starches). As is described by Heyrman et al. (2005, International Journal of Systematic and Evolutionary Microbiology 55: 119-131), B. simplex strains will grow at a range of useful temperatures (growth is observed at 20° C. and 30° C., but not at 45° C.); pH (strains grow “profusely” at pH 9 and pH 7; at pH 5 growth is “variable’); and will react with a broad variety of substrates. However, Heyrman et al. teaches that “no growth occurs in media supplemented with 7% NaCl” and that urease production is “negative”. See Heyrman et al., cited above, page 129.
Such a lack of ability to grow at high salt concentrations has also been reported for other B. simplex strains. For example, Gomaa et al. (2007, Arab J. Biotech. 10(1): 107-116) disclose that a frozen sample of Bacillus simplex TWW-04 showed little growth at 5 mM NaCl while a 36 month subcultured sample exhibited no growth under such conditions.
Bacillus butanolivorans is closely related to B. simplex (having a 16S rRNA homology of 98.3% with Bacillus simplex DSM 1321) and was isolated from soil in Lithuania. B. butanolivorans is particularly effective to degrade n-butanol present in industrial waste streams. See Kuisiene et al. 2008, International Journal of Systematic and Evolutionary Microbiology 58: 505-509. However, like B. simplex, B. butanolivorans will not grow in high salt (e.g., 7% w/v) environments. See Kuisiene et al., cited above.
Accordingly, there is a need for Bacillus strains that grow in high salt environments and exhibit desirable enzymatic activity, including urease activity.